The decision about where to play top prospect Javier Baez is looming as he continues his rise through the Chicago Cubs organization.

Baez, the Cubs' top pick in the 2011 draft, has been on a tear at Double-A Tennessee after being promoted from Single-A earlier this season.

He's played shortstop in the minors but Starlin Castro has that position locked up at the major league level -- at least for now. As Baez gets closer to making the majors the Cubs will need to decide where he will play.

"That is something this offseason we're going to have to get together as an organization and discuss it," Cubs scouting director Jason McLeod said on Wednesday. "First of all where is he going to play this winter and then do we incorporate third base, second base, some other positions for him just so he has the experience? I'm sure as we get into spring training next year you'll see him taking ground balls at other positions just to see what it looks like."

McLeod says that's the pattern for players who might have to switch positions.

"Typically it starts to happen when a guy gets into Double-A and now you're thinking he might be within a year of arriving in the major leagues," McLeod said.

McLeod cited Junior Lake as an example. Lake started taking fly balls last winter and saw time in the infield and outfield this year in the minors, although McLeod pointed out he's played more in the outfield with the Cubs in three weeks than in his whole minor league career.

Some players won't be able to switch. Kane County first baseman Dan Vogelbach, the organization's position player of the month for July, doesn't have the athleticism for any other position and has Anthony Rizzo standing in his way. But as McLeod and senior Cubs brass often say, things will play themselves out.

"That is the easy answer. We don't worry about it until later, and I hope it's something we have to worry about," McLeod said. "Hopefully it forces us to make some tough decisions in the future."

As for Baez, it wouldn't be a surprise to see him at Triple-A Iowa soon. He has 11 home runs at Double-A Tennessee in 121 at-bats going into action on Wednesday night. That's three fewer than the team leader Christian Villanueva, who has 404 at-bats. But defense remains an issue for Baez, who committed 31 errors at Single-A Daytona and has seven at Tennessee.

"Sometimes it's good to get a guy exposure to a higher level that you think he's going to start at next year," McLeod said. "Or a team is in a playoff situation in the minor leagues and you want guys to experience that. You probably will see a few more promotions in the the next week to 10 days just to give guys experience at a certain level going into the offseason."

For example, 2013 second-round pick Rob Zastryzny was just promoted to Single-A Kane County for the rest of this month and pitcher Kyle Hendricks will make his Triple-A debut on Thursday.

The ladder to the majors is starting to get crowded, something Cubs fans have been waiting for.